Answer:

Step-by-step explanation:
 
        
             
        
        
        
Answer:
15/8 hours .................
Step-by-step explanation:
Let L be Laura, and B be Ben. Then:
3L=1
5B=1
Next:
15L=5
15B=3
15(L+B)=5+3=8
15/8 (L+B)=1
 
        
             
        
        
        
Answer:
D) 5
Step-by-step explanation:
Perpendicular lines have opposite reciprocal slopes. 
The line:  has a slope of
 has a slope of  as it is  in y=mx+b form, where m is the slope, and b is the y-intercept.
 as it is  in y=mx+b form, where m is the slope, and b is the y-intercept. 
Since the slope is  , we see that the negative reciprocal slope is
, we see that the negative reciprocal slope is  , as
, as  is the reciprocal (flip the numerator and denominator).
 is the reciprocal (flip the numerator and denominator).
From here, we can use point slope form:  , where
, where  is  the point. In this case, (3, 1) is the point.
 is  the point. In this case, (3, 1) is the point. 
Thus, we have:  as our final equation.
 as our final equation. 
Simplifying: 
And:  , which gives us the y-intercept to be 5.
, which gives us the y-intercept to be 5. 
Let me know if this helps!